period_to_seconds approximately converts a period to seconds assuming
there are 364.25 days in a calendar year and 365.25/12 days in a month.
seconds_to_period create a period that has the maximum number of
non-zero elements (days, hours, minutes, seconds). This computation is exact
because it doesn't involve years or months.
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A numeric object. The number of seconds to coerce into a period.
A number (period) that roughly equates to the period (seconds) given.